Nobara has successfully hit Mahito's soul, injuring both him and his double with Resonance. Recognizing his classmate's cursed technique, Yuji capitalizes and pummels Mahito with rapid-fire cursed energy-infused punches. Resonance's effect is still lingering so Mahito can't move well or fight back.
While Yuji bashes Mahito into a pillar with a relentless barrage of punches, he solemnly thanks Nobara. Yuji believes he hasn't been able to save anyone and that he's wasted everyone's efforts, but Nobara's help has shown him he's still not alone. Inspired by Nobara, Yuji keeps the pressure on and prepares to exorcise Mahito here and now.
Meanwhile, in the alley, the nail drops from Mahito's double's forehead as he affirms her theory about him. Nobara believes their real duel begins now but the double decides to run away instead and heads directly into a subway entrance. Nobara could just ignore him and go to B5F but she has a bad feeling about letting him run loose and decides to exorcise him on the way there.
Before Yuji can finish off Mahito's main body, the special grade splits into several small, spherical versions of himself that run all across the room. One of them flares up its cursed energy to get Yuji's attention. This makes him think that this is Mahito's main body and smashes it. However, this was a feint, and the other doubles reform Mahito's body as he runs away.
Both Mahito's enter the same corridor with the two jujutsu high students chasing them from opposite sides. Yuji initially believes Mahito is trying to heal until he sees Nobara. He immediately yells for her to run away, realizing the danger she's in.
Nobara is surprised to see Yuji and Mahito's real body acted as a blind spot to cover the switch so she wouldn't notice. Furthermore, her fight with the double made her to lower her guard against Mahito's hands. Mahito scores a direct hit on Nobara's face, potentially spelling the end for her. Yuji easily kills the double with a single shot and runs over to check on Nobara. Mahito waits to see if one touch will be enough to kill her since it wasn't enough to kill Nanami in their first encounter.
Nobara touches her face and recalls her life in 2009 when she was an emphatic six-year-old playing Smash Bros. Back then she believed everyone in her hometown was weird and she was the only sane person there.